It is known to encapsulate perfume or other materials, in small capsules (or microcapsules), typically having a diameter less than 1000 microns, for a variety of reasons relating to the protection, delivery and release of the perfume or other material. One type of capsule, referred to as a wall or shell capsule, comprises a generally spherical hollow shell of e.g. perfume-insoluble material, typically polymer material, within which perfume or other material is contained.
If such capsules are incorporated in certain solvent and/or surfactant-containing consumer products, e.g. shampoos, stability problems can arise, with the encapsulated material tending to leach out of the capsules into the product over time, at least in cases where the capsule contents are soluble in ingredients of the product.
The present invention aims to address such stability problems.